Marker lights don't work, turn signals do?

Since the Road crews are migrating from a salt on the roads. To a liquid de-icer,(airports used it for years on planes)

It has a very nasty effect on copper connectors in wire, bulb and switches.

During the spring and summer I spend a month changing (corroded wire/connectors)

You can ask any O/O about wire corrosion has increased rapidly over the recent years past.

 

What and where exactly is the turn signal switch? Do I need to buy a new one or clean the old?...

thanks

 

Wouldn't the obvious place to start be the light cord? I mean it worked before you unplugged it.

 

Yes it would be, I'm tackling this thing on all angels. How would you suggest checking it?.. If moisture got inside would it be no good anymore?...

[[AND I BOUGHT A NEW TURN SIGNAL SWITCH AND INSTALLED, IT LOOKS GOOD BUT ITS NOT THE FIX]]

 

Wires are likely to be loose inside from pulling on the cord instead of the handle. Always start at the last thing done before the problem.

 

First thing I would do is unplug light cord from trailer and see what happens. This will narrow it down to either tractor or trailer. If still shorting out unplug the cord from the tractor side to see if cord is shorting out.

 

Yup, just did that. Unplugged from trailer, actually tried that last night on the side of the road too, lights still shorted, unplugged pigtail from truck, still shorting, ...

unplugged bulbs on left and right side of truck, one at a time to check the circuit, still shorted.
unplugged all tail lights, still shorted.

[now, here's another clue] - all my lights EXCEPT my tail lights will flash, then go off, flash, then go off - ...every trailer light, marker light around the truck will flash for a breif moment, then go off.... Except my tail lights of the tractor


thanks to any new suggestions... I'm really not wanting to throw this at a shop.

 

What make truck is it? If it has circuit breakers instead of fuses it could have a weak circuit breaker that needs to be replaced.

 

Well, it's a 387 Pete (2009)...

 

If everything except the taillights are briefly lighting up, the problem is in the taillights or the wiring to them. Go back there an wiggle stuff around by hand, you might find it that way.